[Lustre-discuss] 8TB Lun Limit

[Aaron Knister]

How difficult would it be to migrate from the ext3 based ldiskfs to zfs?

On Nov 26, 2007, at 1:18 PM, Andreas Dilger wrote:

> On Nov 26, 2007  11:08 -0500, Aaron Knister wrote:
>> Is the 8TB lun size limit going to be lifted any time soon? Because  
>> of
>> this limit I'm only getting 33TB out of 45TB raw using raid5 with
>> terabyte drives. What is everybody else doing for large arrays over  
>> 8TB?
>
> There will be no 8TB limit for new ZFS-based filesystems, available  
> when
> Lustre 1.8 ships (planned for July '08).
>
> For ext3 filesystems, the 8TB limit will be removed once the upstream
> kernel also removes this limit.  For RHEL5 I believe they are working
> on up to 16TB per ext3 filesystem, but it isn't done yet, nor have we
> tested it.  For ext4 based file system code (available from about  
> Linux
> 2.6.22 and on) the 8TB limit was also removed, but we need to port our
> ldiskfs patches over to be ext4 based.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Sr. Staff Engineer, Lustre Group
> Sun Microsystems of Canada, Inc.
>

Aaron Knister
Associate Systems Administrator/Web Designer
Center for Research on Environment and Water

(301) 595-7001
aaron at iges.org